num_list=[[1,2],["tom","jim"],(3,4),["ben"]]
num_list1=num_list.insert(4,"kity")
print(num_list1)

num_list=[[1,2],["tom","jim"],(3,4),["ben"]]
num_list.insert(1,"kity")
print(num_list)
#老师请教下上面两者区别。为什么一个是None。
num_list=[[1,2],["tom","jim"],(3,4),["ben"]]
print(num_list[3])

num_list[1][1]="lucy"
print(num_list)

#第四小题元组不能改变，所以不能把3修改为5.

#第六题
print(num_list[-1::-1])

numbers=[1,3,5,7,8,25,4,20,29]
numbers.sort()
print(numbers)

print(sum(numbers))

numbers.reverse()
print(numbers)


